Segment Information and Foreign Operations - Concentration of Credit Risk (Details) - customer	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Revenue [Member]
Revenue, Major Customer [Line Items]
Number of customers representing significant share	2	2	2	2
Accounts Receivable [Member]
Revenue, Major Customer [Line Items]
Number of customers representing significant share			1		1
Landmark [Member] | Revenue [Member]
Revenue, Major Customer [Line Items]
Percentage share generated by major customers	11.00%	14.00%	10.00%	11.00%
IQE Group Customer [Member] | Revenue [Member]
Revenue, Major Customer [Line Items]
Percentage share generated by major customers		10.00%		11.00%
Osram Opto [Member] | Revenue [Member]
Revenue, Major Customer [Line Items]
Percentage share generated by major customers	12.00%		11.00%
Major Customer One [Member] | Accounts Receivable [Member]
Revenue, Major Customer [Line Items]
Percentage share generated by major customers			12.00%		13.00%
Top Five Major Customers [Member] | Revenue [Member]
Revenue, Major Customer [Line Items]
Number of customers representing significant share	5	5	5	5
Percentage share generated by major customers	37.00%	42.00%	36.00%	42.00%